Apparatus and method for implanting collapsible/expandable prosthetic heart valves

ABSTRACT

Apparatus for delivering a prosthetic heart valve into a patient by means that are less invasive than conventional open-chest, open-heart surgery. The prosthetic valve may be collapsed while in a delivery device. When the valve reaches the desired implant site in the patient, the valve can be released from the delivery device, which allows the valve to re-expand to the configuration in which it can function as a heart valve. For example, the delivery device may be constructed to facilitate delivery of the prosthetic valve into the patient via the apex of the patient&#39;s heart.

This application claims the benefit of U.S. provisional patentapplication 60/937,361, filed Jun. 26, 2007, which is herebyincorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

This invention relates to collapsible/expandable prosthetic heart valvedelivery systems which can house, retain, maintain, transport, deploy,help anchor, and release (and, if necessary, reposition and/or retrieve)a collapsible prosthetic heart valve via a minimally invasive (or atleast reduced invasiveness) port access, e.g., at the apex of apatient's heart and through the intercostal space of the patient's ribs.

The field of collapsible/expandable prosthetic heart valves isrelatively new. The general idea is to provide a prosthetic heart valvethat can be collapsed to a relatively small size (diameter) for deliveryinto the patient with reduced invasiveness to the patient's body(typically via a tube of relatively small diameter). When the valvereaches the desired implant site in the patient, the valve is releasedfrom the delivery apparatus and expanded to its full operating size.This also includes securing the valve to tissue of the patient at theimplant site.

There are several approaches to delivering and deploying suchcollapsible/expandable prosthetic heart valves using arterial or venoussystems of the patient. However, these approaches may impose certainconstraints, such as requiring smaller delivery system profiles (crosssections) so that they can be used in diseased and smaller vessels andto minimize emboli risk. This may result in undesirable trade-offs invalve design and performance in order to accommodate the demand fordelivery of the valve through smaller delivery system profiles.

Ideally, the delivery system should be designed around a durable andefficient valve design, thus not compromising any of the valve'slong-term implant performance requirements. In doing so, the valvedesign should be adequate for its intended performance and long-termdurability functions. This may result in valve profiles in the collapsedstate that are somewhat larger than would be appropriate for humanartery or vein delivery approaches, thereby calling for an alternativeroute to delivering the valve to its intended implant site.

The transseptal (through the septum of the heart) antegrade (delivery inthe same direction as native blood flow) approach is one approach thathas been tried. In the transseptal approach, access is gained throughthe venous circulatory system leading to the right atrium. A puncture ismade through the septum wall separating the left and right atria (hencethe term transseptal). The catheter is then advanced through the mitralvalve into the left ventricle and looped back up ending at the aorticvalve. This approach may have some disadvantages, however. For example,it may result in damage to the mitral valve and the associated chordaewhen trying to gain access to the aortic valve. In contrast, thetransapical (through the apex of the heart) antegrade approach may offera better and safer alternative for entering the left ventricle (“LV”)for direct access to the aortic and mitral valves. (See, for example, P.Tozzi et al., “Endoscopic off-pump aortic valve replacement: does thepericardial cuff improve the sutureless closure of left ventricularaccess?”, European Journal of Cardio-thoracic Surgery 31 (2007) 22-25,available online 6 Sep. 2006.) Accessing the LV through a small port atthe apex (lower end) of the heart is not new, as this has been thepractice for several decades in placing bypass shunts in pediatrics.There are good, long-term, clinical experiences with this accessapproach to render it safe and effective. With an optimum deliverysystem design, safer and more effective direct access to the aortic ormitral valve can be achieved for the purposes of repair and/orreplacement of defective native valves.

SUMMARY OF THE INVENTION

The delivery system of the present invention may comprise severalcomponents working together to facilitate various functions required fordelivery and deployment of a collapsible/expandable prosthetic heartvalve. The delivery system may include an elongated shaft attached to anergonomic handle. The handle may incorporate several controls forseveral functional features within the device. One of these controls maybe a rotating wheel that functions to advance/retract the valve prior todeployment and final release. Another control may be an outer shaft,which may contain a polymer sheath that functions as thevalve-collapsing/expanding mechanism. Inside the outer shaft and withinthe sheath, there may be an internal movable shaft that is connected tothe delivery device tip at the distal end of the delivery system. Theshaft may be notched such that a wheel with teeth can engage and movethe shaft axially when rotated in either direction (advance or retract).The prosthetic heart valve may be mounted onto this shaft and betweenthe tip and a base. The base platform may function as a valve holdingand constraining mechanism. The valve may rest on this base and can besecured in place using various mechanisms. For example, the base canhave features and through-holes to allow the valve's proximal struts tobe securely fastened using a suture that runs to the outside of thedevice at the handle on the proximal end. When the operator is satisfiedwith the position and orientation of the valve, the valve can bereleased by cutting and pulling out this suture. Alternatively, othermechanisms can be employed to secure the valve in place until finalrelease.

The internal movable shaft may contain multi-lumens that connectmanifold ports at the proximal end of the device to one or more openingsat or near the distal end (tip). These lumens can be utilized forvarious functions such as delivery of fluids (saline, contrast, etc.)and deployment of embolic protection devices, balloons forvalvuloplasty, etc.

Outside the outer shaft, a spring-loaded, donut-shaped component can beincluded to aid in sealing the apex of the heart or other access at theentry point by way of gentle pressure driven by the spring.

The delivery system can be manufactured from materials that are known tobe biologically compatible for short-term human interaction, since thisdevice is not a permanent implant. However, material selection shouldtake into account the fact that this device will come into contact witha permanent implant.

The device handle can be injection molded from a bio-compatible polymermaterial. The elongated shaft can be polymeric or laser cut/machinedsurgical grade stainless steel. Internal working components can beeither from a polymeric origin, stainless steel, shape-memory nitinol(nickel/titanium alloy) material, etc., depending on each component'sfunction and performance requirements. The manifold can be an injectionmolded polycarbonate. The sealing donut can be made from variousdurometers of silicone. The device components may fit together usingvarious means of interference fit, tabs, slots, glue, polymer heatbonds, and/or locking mechanisms to facilitate a seamless workingsystem.

Various advantageous features of the invention are identified (to someextent recapitulating the foregoing) in the next several paragraphs.

Certain aspects of the invention relate to providing ergonomic,hand-held, easy-to-use delivery system for collapsible/expandableprosthetic heart valves. Such a delivery system may include a handle andan elongated shaft that houses the valve. The handle can incorporatecontrols for specific functional features within the device.

The delivery system may include valve release, retrieve, and/orreposition mechanisms.

The device may include one or more radio-opaque marker bands (e.g., ator near the distal tip) for guidance and visualization of the deliverysystem (especially the distal end) under fluoroscopy in the case ofall-polymer construction.

The device may include precision, wheel-driven, advance/retractcapabilities for precise valve positioning. Alternate mechanisms (e.g.,a sliding lever) are also possible.

The device may include capabilities for fully deploying the valve butnot releasing it when recapture is desired.

The device may include multi-lumen capabilities in the shaft forprocedural support using ancillary devices such as guide wires, ballooncatheters, embolic protection devices, fluids delivery (flushing orvisualization), etc.

The valve can be secured to internal features of the delivery systemusing different configurations. One way is to secure the proximal end ofthe valve to a holder base (e.g., using sutures, mechanical interferencefit features, etc.). Another way is to utilize a suture (orpolymer-covered thin wire or any other appropriate means similar tothis) to run from the proximal end of the device (handle) throughspecifically designed structures within the valve. This strand can thenrun through specifically designed channels in the device tip and backinside the central lumen (or other specific lumen) and end outside thedevice by the handle where the operator can control it. Tensioning orloosening this wire/suture will cause the valve to deploy orre-collapse. This can be used to partially deploy the valve andrecapture it for repositioning or retrieval as desired.

A movable sheath, with an independent control at the handle, canfunction as the valve collapsing/expanding mechanism byadvancing/retracting the sheath over the valve. The sheath may alsomaintain and protect the valve in the collapsed state. The sheath canalso facilitate partial deployment and expansion of the valve, e.g., sothat the operator of the apparatus can check for appropriate positioningof the valve in the patient.

The device may include features in the tip and valve holder base tocontrol valve orientation within the delivery system so that the valvecan be deployed with the correct angular orientation about itslongitudinal axis, e.g., to align commissures of the prosthetic valverelative to commissures of the native valve as desired. These featurescan be undercuts or depressions that correspond to features on theprosthetic valve, for example.

Along with the conventional purse-string suture, a spring-loaded,silicone, molded, donut-shaped component can aid in sealing the entryport at the apex of the heart or other access into the patient'scirculatory system.

The device may include the capability of opening and closing off accessto any of the lumen ports at the back manifold connector.

The device tip may include features that allow the valve distal end torest in a manner that controls the valve's collapsed diameter (e.g., toprevent damage to the stent and valve leaflets during collapse of thevalve for minimally invasive delivery).

The delivery system can include a fork-like structure that can protrudeand extend outside the shaft near the distal end to force open calcifiednative heart valve leaflets (e.g., into the sinuses of the valsalva) inpreparation for valve deployment and release. Another example of anembodiment for such purposes is to deploy a structure like an umbrella.Such an umbrella design can serve two functions: (1) calcified leafletretention, pushing such native leaflet structures out of the way inpreparation for new valve deployment, and (2) embolic protection, whichcan be achieved by incorporating a fine mesh within the deployed ribs ofthe umbrella, thus capturing any emboli from the procedure. Once theprocedure is completed, this umbrella can be collapsed and retractedback into the shaft, thereby safely removing from the patient all emboliand any calcified debris. An example of a structure that can be used tocollapse the umbrella when desired includes a thin strand (e.g., wire orsuture) attached to each of the umbrella ribs. These strands extend intothe main central lumen. Pulling these strands from the proximal endcauses the ribs of the umbrella to collapse.

The delivery system wheel can be centered in the handle for rotationaccess from both sides of the handle, or it can be offset to protrudefrom only one side of the device handle.

The device preferably contains seals in various areas to prevent bloodfrom seeping through the various channels and outside the heart.

Further features of the invention, its nature and various advantages,will be more apparent from the accompanying drawings and the followingdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified elevational view of an illustrative embodiment ofapparatus in accordance with the invention.

FIG. 2 is a simplified isometric or perspective view of the FIG. 1embodiment.

FIG. 3 is another simplified elevational view (with portions removed toreveal some of the interior) of the FIG. 1 embodiment.

FIG. 4 is a simplified isometric or perspective view of anotherillustrative embodiment of apparatus in accordance with the invention.

FIG. 5 is a simplified partial elevational or perspective view (withportions removed to reveal some of the interior) of the FIG. 4embodiment.

FIG. 6 is a simplified elevational or perspective view of portions ofthe above-mentioned embodiments.

FIG. 7 is a simplified elevational or perspective view of portions ofthe FIG. 4 embodiment.

FIG. 8 is a simplified elevational view (with some portions removed) ofan illustrative embodiment of apparatus that can be like the FIG. 4embodiment, with possible additional structure in accordance with theinvention.

FIG. 9 is another view that is generally like FIG. 8, but for a laterstage in use of the apparatus in accordance with the invention.

FIG. 10 is a simplified isometric or perspective view of portions of theFIG. 4 apparatus.

FIG. 11 is a simplified isometric or perspective view of portions ofFIG. 8.

FIG. 12 is a simplified isometric or perspective view of portions ofFIG. 4.

FIG. 13 is a view similar to FIG. 12 for a later stage of operation ofthe apparatus in accordance with the invention.

FIG. 14 is another view similar to FIG. 13 for a still later stage inoperation of the apparatus in accordance with the invention.

FIG. 15 is still another view similar to FIG. 14 for an even later stagein operation of the apparatus in accordance with the invention.

FIG. 16 is yet another view similar to FIG. 15 for a still later stagein operation of the apparatus in accordance with the invention.

FIG. 17 is a simplified elevational view of an even later stage inoperation of the FIG. 16 apparatus in accordance with the invention.

FIG. 18 is a simplified isometric or perspective view of what is shownin FIG. 17.

FIG. 19 is another view similar to FIG. 18 for a still later stage inoperation of the apparatus in accordance with the invention.

FIG. 20 is a simplified elevational view of what is shown in FIG. 19.

FIG. 21 is a simplified elevational view of an illustrative embodimentof one component from several earlier FIGS.

FIG. 22 is a simplified isometric or perspective view of what is shownin FIG. 21.

FIG. 23 is a view, similar in some respects to FIG. 4, showingillustrative embodiments of possible additional components in accordancewith the invention.

FIG. 24 is a simplified isometric or perspective view of portions ofwhat is shown in FIG. 23.

FIG. 25 is a simplified elevational view of what is shown in FIG. 24.

FIG. 26 is a simplified isometric or perspective view of portions ofwhat is shown in FIGS. 23-25.

FIG. 27 is a simplified, partial, elevational view, partly in section,showing an illustrative embodiment of possible features in accordancewith the invention.

FIG. 28 is a simplified sectional view showing an illustrativeembodiment of other possible features in accordance with the invention.

FIG. 29 is a simplified, partial, elevational view, partly in section,showing an illustrative embodiment of still other possible features inaccordance with the invention.

FIG. 30 is a simplified perspective or isometric view of an illustrativeembodiment of a structure that can be used in apparatus in accordancewith the invention.

DETAILED DESCRIPTION

An illustrative embodiment of prosthetic heart valve delivery apparatus10 in accordance with the invention is shown in FIG. 1. FIG. 1 andseveral subsequent FIGS. omit all depiction of the prosthetic valve, butseveral still later FIGS. do show examples of such valves. Thecomponents of apparatus 10 that are visible in FIG. 1 include handle 20,control wheel 30, outer shaft 40, inner shaft 50, distal tip 60, andproximal (back) manifold connector 70. Elements 40 and 70 are both fixedto handle 20. Control wheel 30 is rotatable about an axis (perpendicularto the plane on which FIG. 1 is drawn) to cause shaft 50 (and distal tip60) to advance or retract relative to shaft 40, depending on thedirection of rotation of the control wheel. Distal tip 60 is fixed onthe distal end of shaft 50. Connector 70 may include one or more lumensthat communicate with one or more lumens through other components of theapparatus.

Elements 20, 30, and 70 remain outside the patient at all times.Elements 40, 50, and 60 are designed for insertion into a patient's bodyin a low invasiveness manner to deliver a prosthetic heart valve intothe patient and to deploy (implant) that prosthetic heart valve in thepatient. More particularly, the prosthetic heart valve is initiallycontained (in a collapsed condition) in a distal portion of apparatus 10(i.e., inside shaft 40, concentrically around shaft 50, and abuttingdistal tip 60). In this condition of the apparatus, shaft 40 may help tokeep the valve collapsed, and distal tip 60 (which is proximallyretracted) may help to keep the valve inside shaft 40. When the distalportion of the apparatus reaches the desired implant site for the valvein the patient, wheel 30 can be rotated to extend distal tip 60, adistal portion of shaft 50, and the prosthetic heart valve from thedistal end of shaft 40. This allows the prosthetic heart valve to expandradially outwardly from shaft 50 to its full operating size, which alsocauses the valve to engage surrounding native tissue of the patient andthereby implant in the patient. The apparatus can then be withdrawn(proximally) from the patient. In particular, distal tip 60 comes outthrough the center of the now-expanded valve.

More details regarding the foregoing will be provided later in thisspecification.

It should be noted that in the FIG. 1 embodiment, shaft 40 is off-centerrelative to handle 20 (i.e., shaft 40 is somewhat below thetop-to-bottom center of handle 20). On the other hand, wheel 30 iscentered on handle 20 and is exposed for operation from either above orbelow the handle.

FIGS. 2 and 3 show other views of apparatus 10. FIG. 3 shows apparatus10 with half of handle 20 removed. This exposes the connection betweenwheel 30 and shaft 50. In particular, it shows that there is a spur gear32 on wheel 30 concentric with the axis of rotation of wheel 30. Thisspur gear engages with a rack 52 on shaft 50. These features allowrotation of wheel 30 to cause translation of shaft 50 along itslongitudinal axis. (Features of this kind may be seen even more clearlyfor another embodiment in FIG. 5.)

An alternative embodiment of device 10 is shown in FIG. 4. Even thoughthe FIG. 4 embodiment is somewhat different than the FIGS. 1-3embodiment, the same reference numbers continue to be used for generallysimilar elements. Thus additional information for such elements can begleaned from earlier description of those elements, and it will not benecessary to repeat everything previously said for elements that areused again (at least in generally similar form) in differentembodiments.

The FIG. 4 embodiment is different from the FIGS. 1-3 embodiment in thatin FIG. 4 shaft 40 is centered (from top to bottom) on handle 20.Another difference is that in FIG. 4, control wheel 30 is only operablefrom the top of handle 20.

FIG. 4 shows the possible addition of a toroidal or donut-shaped sealingring 80 disposed concentrically around an intermediate portion of thelength of shaft 40. Ring 80 fits relatively closely around the outsideof shaft 40, but ring 80 is also axially slidable along shaft 40. Ifring 80 is moved in the proximal direction from the approximate startingposition shown in FIG. 4, coil spring 90 (also disposed concentricallyaround shaft 90) acts to resiliently urge it back toward the startingposition. Ring 80 can be located along shaft 40 so that when the distalportion of shaft 40 is pushed through an opening (aperture) in the apexof the patient's heart or other access to the patient's circulatorysystem, ring 80 bears against the outer surface of the tissue around theaperture and helps to reduce blood leakage from the circulatory systemvia the aperture. Spring 90 keeps ring 80 resiliently pressed againstthe outside of the tissue for this purpose. Ring 80 may be made of asofter material than other components of apparatus 10. For example, ring80 may be made of silicone.

FIG. 5 shows an enlargement of a portion of the FIG. 4 embodiment withpart of handle 20 removed. Thus FIG. 5 shows the spur gear 32 on wheel30 engaging the rack 52 on shaft 50 as described earlier in connectionwith FIG. 3. FIG. 5 also shows a tube 100 that may extend from connector70 to a distal portion of the apparatus. For example, tube 100 mayextend to opening 62 in the distal end of tip 60 for allowing fluidintroduced via connector 70 to be released into the patient from thedistal end of tip 60 for such purposes as providing fluoroscopicallyvisible contrast in the patient. There may be more than one such tube100, which may go to different destinations in the device, and which maybe for different purposes. Note that shaft 50 may be translatableaxially (i.e., lengthwise) relative to tube 100.

FIG. 6 shows portions of elements 40 and 50 and element 60 on a largerscale. FIG. 7 does the same for a portion of element 20 and element 70.FIG. 7 also shows that element 70 may include a valve 72 for selectivelyclosing a lumen through that element. In particular, valve 72 may becontrolled by the operator of the apparatus to close a lumen throughconnector 70, e.g., to prevent blood from escaping from the patient viathat lumen. When desired, the operator may open valve 72, e.g., to allowfluid or some other auxiliary material or apparatus to be introducedinto the patient via the associated lumen. Depicted valve 72 may berepeated for other lumens if desired.

FIG. 8 shows an illustrative embodiment of a possible addition to whathas been shown before. In particular, FIG. 8 shows that a plurality offingers 110 may be selectively deployed from the distal end of shaft 40(when distal tip 60 is moved somewhat away from that distal shaft end)to push back native leaflets of a patient's native heart valve (which isgoing to be replaced by the prosthetic heart valve delivered by device10). Fingers 110 may be initially confined in an annular array inside adistal portion of shaft 40. When it is desired to deploy them (typicallywhen the distal portion of the apparatus is appropriately positionedrelative to the native valve that is to be replaced), fingers 110 can bepushed (part way) from the distal end of shaft 40, and they thenresiliently extend (radially) out farther from central shaft 50, albeitstill in an annular array as shown in FIG. 8. In this condition, fingers110 push back the leaflets of the native valve (e.g., into the patient'snative valsalva sinus) in order to help make appropriate room fordeployment of the prosthetic valve within the native valve. As shown inFIG. 30, fingers 110 may be attached to a shaft 112 that runslongitudinally inside shaft 40 into handle 20. Fingers 110 and theirshaft 112 can be advanced or retracted relative to shaft 40 via asliding control, lever, or the like that is on the outside of handle 20.For example, FIG. 30 shows a control member 114 attached to the proximalend of shaft 112. Control member 114 can project from a slot in a sideof handle 20, where it can be manipulated by the user of the apparatusto advance or retract fingers 110. Alternatively, control member 114 mayconnect to another actuator element on handle 20 for the same purpose asdescribed in the preceding sentence.

FIG. 9 shows a structure similar to what is shown in FIG. 8, with theaddition of prosthetic valve 200 now deployed from near the distal endof the apparatus. Subsequent FIGS. show valve 200 and its deployment ona larger scale and in more detail, so more detailed discussion of thevalve will be provided later in connection with those other FIGS. Hereit is preliminarily noted that the principal components of valve 200include an annular framework 210 (e.g., of metal) and a plurality offlexible valve leaflets 220 disposed within and mounted on thatframework. Framework 210 and leaflets 220 are radially collapsible to acircumferential size that can fit inside shaft 40. However, when shiftedbeyond the distal end of shaft 40 as shown in FIG. 9, framework 210 canresiliently expand (as shown in FIG. 9), carrying leaflets 220 with theframe and positioning those leaflets relative to one another so thatthey can operate as a one-way, blood flow, check valve (like the nativeheart valve being replaced).

FIG. 10 shows elements 80 and 90 (and portions of neighboring elements)on a still larger scale. FIG. 11 does the same for elements 110 andportions of neighboring elements. Note the opening 62 in the distal endof tip 60, which opening may communicate with a lumen throughabove-described tube 100.

FIGS. 12-20 show an illustrative embodiment of how valve 200 may bedeployed. These FIGS. focus on valve 200 and the distal portion ofdelivery apparatus 10. FIG. 12 shows this portion of the apparatus inthe condition that it has as it is being introduced into the patient(e.g., via an aperture in the apex of the patient's heart). Note thattip 60 is against the distal end of shaft 40 to give this portion of theapparatus a smooth exterior surface.

When the distal portion of apparatus 10 reaches the desired location inthe patient (i.e., the desired location for implanting the prostheticheart valve), distal tip 60 and some associated structure may bedisplaced distally from the distal end of shaft 40 as shown in FIG. 13.This may be done by rotating wheel 30. In addition to what has beenshown in earlier FIGS., FIG. 13 shows that the apparatus may include asleeve 120 around the outside of collapsed valve 200, but insidecollapsed fingers 110. This sleeve may help to protect valve 200 fromfingers 110, and it may also facilitate the staged deployment of valve200. As FIG. 13 shows, sleeve 120 initially moves in the distaldirection with tip 60 and other elements that are inside sleeve 120.

The next step is shown in FIG. 14. In this step, fingers 110 are pushedpart way out of the distal end of shaft 40 so that these distal portionsof fingers 110 can spread radially outwardly and thereby push back theleaflets of the patient's native heart valve. A point should be madehere as follows. FIG. 14 and subsequent FIGS. may show the apparatusthat is inside deployed fingers 110 at locations that are more distal tofingers 110 than would actually be the case. For example, elements 120and 60 may not be distally as far from fingers 110 after deployment ofthose fingers as is shown in FIG. 14 (and subsequent FIGS.). Instead,valve 200 may be deployed closer to deployed fingers 110 than the FIGS.alone may suggest. The FIGS. deviate from what may be the actualpractice in this respect so that various parts can be seen more clearly(i.e., without overlapping and thereby obscuring one another).

The next step is illustrated by FIG. 15. In this step, sleeve 120 ispulled back proximally to begin to expose prosthetic heart valve 200.Although not shown in full detail in FIG. 15 to avoid over-complicatingthe drawing, the distal portion of heart valve 200 typically begins todeploy (i.e., expand radially outwardly as indicated by arrows 202) asit is released from confinement within sleeve 120. Thus the actualcondition of valve 200 in FIG. 15 is typically more like what is shownin FIG. 29 (i.e., distal portion of valve (beyond sleeve 120) expandedradially out; proximal portion of valve (still within sleeve 120) stillprevented by sleeve 120 from expanding radially out).

FIG. 16 shows sleeve 120 pulled proximally back even farther so thatvalve 200 is now completely exposed. Once again, to avoidover-complicating the drawing, FIG. 16 omits the fact that at this stageheart valve 200 is typically expanded radially outwardly along itsentire length as indicated by the arrows 202 and 204 in FIG. 16 and asis actually shown in FIG. 17. FIG. 16 does, however, serve to illustratethe point that prior to the deployment of valve 200 (i.e., prior to itsradial outward expansion), the axial position of the collapsed valve ismaintained in the apparatus by positioning the valve between distal tip60 and a more proximal collar 140 on shaft 50.

FIGS. 17 and 18 show additional structure that may be included inaccordance with the invention. This is a system of flexible strands 130that may be used (in conjunction with distal re-advancement of sleeve120) to re-collapse valve 200 (either partly or wholly) in the eventthat it is found desirable or necessary to reposition the valve in thepatient or to completely remove the valve from the patient after thevalve has been partly or wholly expanded radially outwardly in thepatient. FIGS. 17 and 18 show the routing of strands 130 in thisembodiment. A typical strand 130 comes from a proximal portion of theapparatus between shaft 50 and sleeve 120. The strand 130 passes throughan aperture in collar 140, and then runs along the outside of valve 200to an aperture in distal tip 60. The strand passes through the interiorof tip 60, and then through the central lumen of shaft 50, extendingproximally all the way to the handle, where the strand ends can becontrolled by the operator of the apparatus. There can be any number ofsimilarly routed strands 130 spaced in the circumferential directionaround the apparatus and valve 200. Strands 130 are shown in arelatively loose or relaxed condition in FIGS. 17 and 18. However, theycan be tightened by pulling on their proximal portions.

An example of how strands 130 may be used is as follows. The gradualproximal retraction of sleeve 120 (described in earlier paragraphs)allows heart valve 200 to gradually deploy radially outwardly. Strands130 are relaxed or loose at this time. The gradual deployment of valve200 may be observed by the operator of the apparatus (e.g., via x-ray,fluoroscopy, or the like). If the valve is not going in as desired,expansion of the valve can be stopped by stopping the proximalretraction of sleeve 120. Strands 130 can then be tightened by pullingproximally on their proximal portions, and at the same time sleeve 120can be pushed in the distal direction. This combination of tighteningstrands 130 and pushing distally on sleeve 120 causes valve 200 tocollapse back into the sleeve. The apparatus can then be repositioned toreposition valve 200 in the patient (after which the valve can bedeployed again), or alternatively the valve can be completely removedfrom the patient with all of the surrounding instrumentation. Assumingthat the valve remains in the patient, then when the operator of theapparatus is satisfied with its deployed position and condition, strands130 can be removed (or effectively removed) by pulling on one proximalportion of each strand until the other end of that strand has been pastvalve 200 two times (once going in the distal direction, and then goingin the proximal direction). FIGS. 19 and 20 show the condition of theapparatus after strands 130 have thus been removed (or effectivelyremoved).

Strands 130 can be made of any suitably tensilely strong but laterally(transversely) flexible material. Examples include suture material,metal wire, or the like.

Because FIGS. 19 and 20 show valve 200 in the fully deployed conditionand after strands 130 have been removed, these FIGS. offer the clearestviews of valve 200 and therefore afford the best reference for thefollowing further description of the valve. Although this description isprovided in connection with FIGS. 19 and 20, it will be understood thatthe valve can be the same in all of the earlier-discussed FIGS. herein.On the other hand, it will also be understood that this particularconstruction of the prosthetic heart valve is only an example, and thatmany modifications, variations, and alternatives are also possible forthe valve.

As was mentioned earlier in this specification, principal components ofvalve 200 include frame 210 (e.g., of a highly elastic metal such asnitinol) and a plurality of leaflets (e.g., three leaflets) 220 of aflexible material such as tissue that has been rendered effectivelyinert and otherwise made suitable for long-term, non-reactive use in apatient's body. Leaflets 220 are secured to frame 210 in such a way thatthe leaflets can open (to allow blood to flow through the valve fromleft to right as viewed in FIGS. 19 and 20) and close (to prevent bloodfrom flowing through the valve from right to left as viewed in theseFIGS.).

The illustrative configuration of valve 200 that is shown in the FIGS.herein is particularly adapted for use as a prosthetic aortic valve.Details of valve 200 will therefore be described in that context. Itwill be understood, however, that this is only an example, and that theprosthetic valve can be alternatively configured differently in somerespects to adapt it for use as a replacement for other valves in theheart or circulatory system.

Frame 210 is preferably a continuous, one-piece, annular (ring-like)structure (e.g., a structure that has been cut (using a laser) from atube and then further processed to achieve a desired shape). Frame 210has a “lower” (upstream or blood inflow) portion 212 that extends in aserpentine (undulating or zig-zag) fashion all the way around the valve.This portion of frame 210 may be designed for implanting in or near thepatient's native valve annulus. Frame 210 also includes an “upper”(downstream or blood outflow) portion 216 that also extends in aserpentine (undulating or zig-zag) fashion all the way around the valve.This portion of frame 210 may be designed for implanting in thepatient's aorta downstream from the valsalva sinus of the patient. Frameportions 212 and 216 are connected to one another by a plurality oflinks or struts 214 that extend between those other frame portions atlocations that are spaced from one another around the valve. Struts 214may bow or bulge radially outwardly (as shown) to follow the innersurface of lobes of the valsalva sinus.

Frame 210 may include commissure post members 218 that extend up fromlower portion 212 at appropriate locations around the valve (analogousto the commissures of the patient's native heart valve). These posts 218can form important portions of the frame structure to which leaflets 220are attached.

Frame 210 may also include other structures 219 that extend up andincline radially out from lower portion 212 to help hold back thepatient's native valve leaflets, which (to the extent left remaining inthe patient) are no longer functional.

Frame 210 may also include barbs (e.g., 211) at various locations toengage (and possibly penetrate) the patient's native tissue to help holdthe valve in place where deployed in the patient.

The point of making annular frame portions 212 and 216 serpentine is tofacilitate annular (circumferential, radial) collapse and subsequentre-expansion of the valve. Such collapse is preferably elastic, and thesubsequent re-expansion is preferably resilient.

Although not shown herein, it will be understood that valve 200 may alsoinclude other components such as one or more layers of fabric and/ortissue on various parts of the valve. Such additional layers may be forsuch purposes as to promote tissue in-growth, to reduce the amount ofcontact between frame 210 and surrounding native tissue, to preventmoving portions of leaflets 220 from contacting frame 210, etc.

Illustrative details for collar 140 are shown in FIGS. 21 and 22. Thesefeatures may include a distally extending, radially outer rim 142,within which a proximal portion of valve 200 can be received when thevalve is in the collapsed condition. This structure 142 can help to keepvalve 200 confined to its collapsed condition prior to deployment.

Other features of collar 140 may include recesses or sockets 144, intowhich extreme proximal portions (e.g., 211) of frame 210 may extend whenvalve 200 is in the collapsed condition. Such engagement between frame210 and collar 140 can help ensure that valve 200 always maintains aknown rotational (angular) orientation about the longitudinal axis ofthe apparatus. This can be helpful to ensure that rotation of apparatus10 about its longitudinal axis produces exactly the same rotation ofvalve 200 about that axis. This may be important, for example, to helpthe operator of the apparatus position valve 200 for deployment withcommissure posts 218 in a desired rotational or angular positionrelative to the patient's native valve commissures. As a specificexample, it may be desirable for each commissure post 218 to be alignedwith and inside a respective one of the patient's native valvecommissures. This may necessitate rotation of apparatus 10 about itslongitudinal axis, and features like 144 (with certain valve framefeatures received within those features 144) can help ensure that valve200 has a known angular relationship to apparatus 10, and that thisangular relationship is always maintained until the valve is deployedfrom the apparatus. Snug engagement between collar 140 and shaft 50 isalso part of this aspect of the invention in this embodiment.

Still other possible features of collar 140 are apertures 146 forpassage of above-described strands 130 through the collar.

FIGS. 23-26 illustrate another possible feature of the apparatus. Thisis an embolic protection structure 300, which may also include featuresfor pushing back the leaflets of the native heart valve that is to bereplaced by the prosthetic valve. Structure 300 will now be described.

A purpose of apparatus 300 is to capture any debris (e.g., emboli) thatmay be dislodged from inside the patient during deployment of prostheticheart valve 200 and/or the expansion of fork fingers 110. Thus embolicprotection apparatus 300 is typically deployed in the patient, early inthe procedure, downstream from the location at which valve 200 will bedeployed. For example, assuming that valve 200 is a replacement for thepatient's native aortic valve, apparatus 300 may be deployed in thepatient's aorta downstream from where the prosthetic valve will beemployed. Apparatus 300 acts like a blood filter. It allows blood toflow through, but it captures any particles or the like that should notbe allowed to remain in the patient's blood stream. After prostheticvalve 200 has been implanted, apparatus 300 is collapsed (stillretaining any debris it has captured) and removed from the patient inthe opposite way from which it was introduced.

In this embodiment, apparatus 300 is a structure somewhat like anumbrella. In particular, structure 300 has a central shaft 310, and aplurality of ribs or spokes 320 that are attached to a distal portion ofshaft 310 and that can either collapse inwardly against (parallel to)shaft 310 or that can incline radially outwardly from shaft 310. Anotherelement of structure 300 is a flexible, emboli-catching web or mesh(blood filter) 330 attached to ribs 320. Still other components ofstructure 300 are tethers 340 (shown only in FIG. 26 to avoidover-complicating the other FIGS.). Tethers 340 run inside the proximalportion of shaft 310 and come out of apertures in the side wall of shaft310 at locations that are adjacent to ribs 320. Each tether 340 isattached to a respective one of ribs 320.

Before deploying valve 200, apparatus 300 may be introduced into thepatient in a collapsed condition via proximal connector 70, a lumenthrough tube 100, and distal tip aperture 62. When apparatus 300 is atthe desired location in the patient's circulatory system downstream fromwhere valve 200 is to be implanted, the proximally directed tension onproximal portions of strands 340 may be released. This allows ribs 320to resiliently deflect outwardly into an array somewhat like the ribs orspokes of an open umbrella. Ribs 320 carry out with them, and thus alsoopen, blood filter web 330. These structures (i.e., 320 and 330)preferably bear against an annular portion of the inner surface of ablood vessel (e.g., the aorta) downstream from where valve 200 will beimplanted in the patient.

After valve 200 has been deployed, embolic protection apparatus 300 maybe collapsed again by pulling proximally on tethers 340. This causesribs 320 to again become parallel to and against central shaft 310.Blood filter 330 (with any captured debris) is thereby also collapsedagainst central shaft 310. This allows apparatus 300 to be pulled backinto device 10 via the aperture 62 in distal tip 60.

Note that apparatus 300 may include ribs 320 that extend proximally backfrom blood filter 330 per se. These rib extensions may serve theadditional function of pushing back (radially outwardly) the leaflets ofthe patient's native heart valve prior to deployment of prosthetic valve200.

After apparatus 300 (with above-mentioned, optional, proximal, ribextensions) has been deployed, the distal portion of device 10 may bemoved distally closer to apparatus 300. The distal portion of device 10may then be opened and valve 200 may be deployed as shown in FIGS.23-25. Because in this embodiment, deployed valve 200 may somewhataxially overlap with the proximal extensions of ribs 320, afterdeployment of valve 200, apparatus 300 may first be pushed in the distaldirection to eliminate this overlap so that apparatus 300 can bere-closed without disturbing implanted valve 200. This is also aconvenient point to mention that after valve 200 has been deployed (inany embodiment, with or without apparatus 300), shaft 40 may be pusheddistally through the implanted valve to again close against distal tip60. This restores the smooth outer surface to device 10, whichfacilitates proximal withdrawal of device 10 through the implanted valvewithout disturbing the valve. If apparatus 300 is employed, it ispreferably collapsed and returned to the interior of device 10 (orcompletely removed via device 10) prior to full withdrawal of device 10through the implanted valve.

FIG. 27 shows that a lumen through elements 70, 100, 60, 62 can be usedfor passage of a guide wire 400 through the apparatus. Thus a guide wire400 can first be placed in the patient, and device 10 can thereafter beintroduced into the patient by following along this guide wire. Thisguide wire lumen and/or other similar lumens through device 10 canalternatively or additionally be used for other purposes such asflushing, introduction and/or removal of other ancillary devices (e.g.,embolic protection apparatus 300), etc.

FIG. 28 shows other possible aspects of valve deployment and retrieval.FIG. 28 shows the upstream end of valve 200 inside sheath 120 andbearing on collar 140. Suture or wire strands 500 pass through collar140 and are looped through upstream portions 212 of valve frame 210.Strands 500 can be pulled in the proximal direction to hold the proximal(upstream) end of valve 200 against collar 140. This also prevents theproximal end of valve 200 from expanding radially outwardly (even whensheath 120 is retracted proximally). However, when sheath 120 isretracted proximally past the proximal end of valve 200 and the tensionon strands 500 is relaxed, the proximal end of valve 200 can expandresiliently outwardly. (FIG. 29 shows this structure again (although itomits depiction of strands 500 to avoid over-complicating the drawing)with the distal (downstream) portion of valve 200 released from sheath120 and resiliently expanded outwardly, but with the proximal portion ofthe valve not yet released.)

FIGS. 28 and 29 show that the distal end of sheath 120 may flareradially outwardly as shown at 122. This feature and strands 500 can beused to re-collapse valve 200 prior to its final release from device 10if for any reason it is desired to reposition the valve in the patientor remove the valve from the patient. A combination of pullingproximally on strands 500 and pushing sheath 120 distally can be used tocollapse valve 200 back down into sheath 120 with the proximal end ofthe valve seated against collar 140. The valve can then either bepositioned differently in the patient and again deployed, or the valvecan be completely removed from the patient with device 10. Assuming thatvalve 200 is going to be implanted in the patient, when the operator ofthe apparatus is satisfied with the placement of the valve in thepatient, the valve is finally released from device 10 by allowing thedownstream end of the valve to deploy and anchor against the aorticwall, and then deploying the upstream valve end. Finally, strands 500are removed by releasing one end of each strand loop and using the otherend of that loop to pull the released end sufficiently far so that thestrand no longer prevents release of the valve from device 10.

It will be understood that the foregoing is only illustrative of theprinciples of the invention and that various modifications can be madeby those skilled in the art without departing from the scope and spiritof the invention. For example, the shapes and sizes of variouscomponents can be different from the shapes and sizes employed in theillustrative embodiments shown herein. As another example, the lateralstiffness of shaft 40 and/or other longitudinal elements within shaft 40can be selected to render the apparatus suitable for different possibleuses and/or preferences. Thus in some embodiments it may be desirablefor the shaft portion of the apparatus to be relatively stiff or evenrigid or substantially rigid (i.e., not flexible or bendable transverseto or laterally of its longitudinal axis). On the other hand, in otherembodiments it may be desirable for the shaft portion of the apparatus(or certain parts of the shaft portion) to be more laterally flexible.

1. Apparatus for delivering a prosthetic heart valve into a patientcomprising: a hollow, tubular, longitudinal, outer shaft extending froma proximal portion of the apparatus to a distal portion of theapparatus; a longitudinal inner shaft disposed inside the outer shaftand substantially longitudinally aligned therewith, the inner shaftbeing longitudinally movable relative to the outer shaft; a tipstructure mounted on a distal portion of the inner shaft forsubstantially closing a distal end of the outer shaft when the innershaft is pulled proximally back relative to the outer shaft; and aprosthetic heart valve disposed around the inner shaft proximal of thetip structure and inside a distal portion of the outer shaft, the heartvalve being releasable from the apparatus when the distal tip is moveddistally away from the distal end of the outer shaft and the heart valveis shifted distally beyond the distal end of the outer shaft.